function changehy(Str) {
    if (Str == 1) {
        document.getElementById('hyt1').style.backgroundColor="#fff";
        document.getElementById('hyt2').style.backgroundColor="";
        document.getElementById('hyt3').style.backgroundColor="";
        document.getElementById('hycon1').style.display="";
        document.getElementById('hycon2').style.display="none";
        document.getElementById('hycon3').style.display="none";

    }
    if (Str == 2) {
        document.getElementById('hyt1').style.backgroundColor="";
        document.getElementById('hyt2').style.backgroundColor="#fff";
        document.getElementById('hyt3').style.backgroundColor="";
        document.getElementById('hycon1').style.display="none";
        document.getElementById('hycon2').style.display="";
        document.getElementById('hycon3').style.display="none";
    }
    if (Str == 3) {
        document.getElementById('hyt1').style.backgroundColor="";
        document.getElementById('hyt2').style.backgroundColor="";
        document.getElementById('hyt3').style.backgroundColor="#fff";
        document.getElementById('hycon1').style.display="none";
        document.getElementById('hycon2').style.display="none";
        document.getElementById('hycon3').style.display="";
    }

}

function changedivp(Str) {
    if (Str == 1) {
        document.getElementById('ppmod1').style.background="url(../images/bg_class_w.jpg) repeat-x top left";
        document.getElementById('ppmod2').style.background="";
        document.getElementById('psd-list').style.display="";
        document.getElementById('ppt-list').style.display="none";
    }
    if (Str == 2) {
        document.getElementById('ppmod1').style.background="";
        document.getElementById('ppmod2').style.background="url(../images/bg_class_w.jpg) repeat-x top left";
        document.getElementById('psd-list').style.display="none";
        document.getElementById('ppt-list').style.display="";
    }
}